695 research outputs found
More on microstate geometries of 4d black holes
We construct explicit examples of microstate geometries of four-dimensional
black holes that lift to smooth horizon-free geometries in five dimensions.
Solutions consist of half-BPS D-brane atoms distributed in .
Charges and positions of the D-brane centers are constrained by the bubble
equations and boundary conditions ensuring the regularity of the metric and the
match with the black hole geometry. In the case of three centers, we find that
the moduli spaces of solutions includes disjoint one-dimensional components of
(generically) finite volume.Comment: 25 page
Lunar impact flashes from Geminids, analysis of luminous efficiencies and the flux of large meteoroids on Earth
We analyze lunar impact flashes recorded by our team during runs in December
2007, 2011, 2013 and 2014. In total, 12 impact flashes with magnitudes ranging
between 7.1 and 9.3 in V band were identified. From these, 9 events could be
linked to the Geminid stream. Using these observations the ratio of luminous
energy emitted in the flashes with respect to the kinetic energy of the
impactors for meteoroids of the Geminid stream is estimated. By making use of
the known Geminids meteoroid flux on Earth we found this ratio to be
2.1x10 on average. We compare this luminous efficiency with other
estimations derived in the past for other meteoroid streams and also compare it
with other estimations that we present here for the first time by making use of
crater diameter measurements. We think that the luminous efficiency has to be
revised downward, not upward, at least for sporadic impacts. This implies an
increase in the influx of kilogram-sized and larger bodies on Earth that has
been derived thus far through the lunar impact flash monitoring technique
Propiedades psicométricas, estructura factorial y validez de constructo de la versión española de la escala de Alofilia.
The aim of this study is to adapt and to obtain evidences of validity of the Allophilia Scale to Spanish population. Participants were 960 individuals from all over Spain. Questionnaires to measure prejudice toward North African people, stress and empathy were used to analyze the criterion validity of the Allophilia scale. Confirmatory factor analysis showed that the items of the questionnaire fit a model with five factors, corresponding to the dimensions proposed by the original authors (affection, comfort, kinship, engagement, enthusiasm). Additionally, it has been found that the Allophilia scale is related with other variables such as prejudice toward North African people (cognitive, emotions and behaviors), stress (interaction, resources, identity) and empathy. In light of these results, we conclude that the questionnaire is methodologically valid and can be used by the scientific community to measure cooperative and participatory intergroup behavior and as a complement to traditional measures of prejudice and negative intergroup behaviors.La Alofilia puede definirse como las actitudes positivas hacia diferentes exogrupos. El objetivo de este estudio es traducir y validar la escala de Alofilia en población española. Método: 960 participantes de todo el territorio nacional formaron parte de la muestra. Se usaron cuestionarios sobre el prejuicio hacia los magrebíes, estrés y empatía para medir la validez convergente y divergente de la escala de Alofilia. Resultados: El análisis factorial confirmatorio puso de manifiesto que los ítems ajustaban un modelo de 5 factores que corresponden a las dimensiones propuestas por los autores originales (Afecto, Comodidad, Afinidad, Compromiso, Entusiasmo) y que éstos están relacionados. También se hallo que los alphas de Cronbach de las diferentes sub-escalas, así como de la escala total, eran elevados. Además, se encontró que la escala de Alofilia se relacionaba con el prejuicio hacia los magrebíes (cognitivo, emociones y comportamientos), el estrés (interacción, recursos e identidad) y la empatía. Discusión: A la luz de estos resultados se concluye que el cuestionario es metodológicamente válido y que puede ser usado por la comunidad científica para medir comportamientos intergrupales cooperativos y participativos y como un complemento a las medidas tradicionales que se centran exclusivamente en el prejuicio y otras actitudes negativas
Unoriented Quivers with Flavour
We discuss unoriented quivers with flavour that arise from D3-branes at local
orbifold singularities, in the presence of Omega-planes and non-compact
D7-branes. We produce a wide class of unoriented quiver gauge theories,
including new instances of N=1 superconformal theories. We then consider
unoriented D-brane instanton corrections of both `gauge' and `exotic' kinds. In
particular, we show that conformal symmetry can be dynamically broken via the
generation of exotic superpotentials. Finally we discuss aspects of the
recently proposed N=1 remnant of N=4 S-duality. We identify new candidate dual
pairs for the C^3/Z_n series of unoriented quiver gauge theories with n odd.Comment: 39 pages, 5 figures, 5 tables. v2: typos corrected, added one extra
model to table 2, matches published version on JHE
Asco físico, aversión a los gérmenes y actitudes antiobesos: el efecto mediacional de la percepción de controlabilidad del peso
Antifat attitudes refer to stereotyping based on people’s weight. A potential explanation for the strong negative attitudes toward obese individuals relates to people’s emotional reactions. In this study, conducted with 373 female students, it is suggested that physical disgust, germ aversion and perceived controllability of weight play a central role in explaining the individual differences that exist in antifat attitudes. Our results showed a positive relationship between physical disgust and germ aversion. Additionally, it has been found a positive correlation between physical disgust and perceived controllability of weight. Furthermore, a positive relationship between antifat attitudes, physical disgust and germ aversion was found. Finally, perceived controllability of weight was positively related with antifat attitudes. The path analysis conducted showed the mediational effect of perceived controllability of weight in the relationship between physical disgust and antifat attitudes. Finally, it is discussed the results in the frame of antifat attitudes literature.Las actitudes antiobesos se refieren a los estereotipos basados en el peso de las personas. Una posible explicación de las actitudes negativas hacia las personas obesas se basa en las reacciones emocionales suscitada por el sobrepeso. En este estudio, realizado con 373 estudiantes de género femenino, se sugiere que el asco físico, la aversión a los gérmenes y la percepción de controlabilidad del peso juegan un papel central explicando las diferencias individuales en lo que respecta a las actitudes antiobesos. Nuestros resultados mostraron una correlación positiva entre asco físico y aversión a los gérmenes. Adicionalmente se halló una correlación positiva entre asco físico y percepción de controlabilidad del peso. También se encontró a una relación positiva entre actitudes antiobesos, asco físico y aversión a los gérmenes. Finalmente, se hallo que la percepción de controlabilidad del peso se relacionaba positivamente con las actitudes antiobesos. El análisis path realizado pone de manifiesto que la percepción de controlabilidad del peso media la relación existente entre el asco físico y las actitudes antiobesos. Finalmente, se discuten los resultados dentro del marco de la literatura sobre las actitudes antiobesos
Post Newtonian emission of gravitational waves from binary systems: a gauge theory perspective
We derive a gauge inspired combinatorial formula based on localization for
the Post-Newtonian expansion of the gravitational wave form luminosity of
binary systems made of objects with very different masses orbiting at large
distances and small velocities. The results are tested against previous
formulae in the literature for Schwarschild and Kerr black holes at the 5th and
3rd Post Newtonian order respectively beyond the quadrupole approximation.
Tidal effects show up in the wave form at the 5th PN order, providing a
quantitative measure of the blackness/compactness properties of the heavy
object.Comment: 29 pages, few notations changed hoping to make the paper more
readable. few typos corrected. version to appear in JHE
On irregular states and Argyres-Douglas theories
Conformal theories of the Argyres-Douglas type are notoriously hard to study
given that they are isolated and strongly coupled thus lacking a lagrangian
description. In flat space, an exact description is provided by the
Seiberg-Witten theory. Turning on a -background makes the geometry
``quantum" and tractable only in the weak curvature limit. In this paper we use
the AGT correspondence to derive -exact formulae for the partition
function, in the nearby of monopole points where the dynamics is described by
irregular conformal blocks of the CFT. The results are checked against those
obtained by the recursion relations coming from a conformal anomaly in the
region where the two approaches overlap. The Nekrasov-Shatashvili limit is also
discussed. Finally, we comment on the existence of black holes in De Sitter
space whose low energy dynamics is described by an Argyres-Douglas theory.Comment: 26 page
Concepto de proyecto: lecciones de experiencia
El concepto de “proyecto” engloba una disparidad semántica que se extiende en todos los ámbitos de la actividad profesional y no profesional. Dentro de la actividad profesional destacan los proyectos que incorporan la ingeniería para la transformación de la realidad. Situándose en el ámbito de los proyectos de ingeniería, y comenzando por las raíces etimológicas de los términos, se efectúa una revisión de las definiciones dadas por diferentes autores y su relación con las corrientes sociológicas de las últimas décadas. El proyecto de ingeniería, que surgió como una herramienta para el desarrollo de ideas tecnológicas, se ha ido enriqueciendo con el pensamiento normativo-legal, con las variables económico-financieras, los parámetros de gestión, y más recientemente, con los aspectos medioambientales. Sin embargo, los proyectos de ingeniería afectan e inciden directamente sobre las personas, involucrando a grupos, agentes, organizaciones, empresas e instituciones. En la actualidad, se consideran esenciales las implicaciones sociales en los proyectos, sin embargo la tecnología para la integración social en estos no está consolidada. Esta comunicación pretende aportar un nuevo marco basado en la experiencia para el desarrollo de los proyectos de ingeniería en el contexto del “desarrollo humano”, situando a las personas en el centro del proyecto
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